CN117203063A - Method for locally coloring plastic parts using solid dyes in a color carrier layer - Google Patents

Abstract

The invention relates to a method for locally coloring, in particular for color laser engraving, plastic parts, preferably thermoplastic parts, very particularly preferably thermoplastic parts comprising a layer structure, comprising the steps of: i) Providing a plastic part (a) having at least one surface; ii) applying a coloured tape to at least a portion of at least one surface of the plastic part (a) to obtain a surface of the plastic part (a) covered with coloured tape; iii) Irradiating the plastic part (a) from ii) with focused electromagnetic radiation (C), preferably non-ionizing electromagnetic radiation (C), on at least a part of the surface of the plastic part (a) covered with the colored band, wherein said local coloring is effected on the plastic part (a) substantially only at the locations irradiated in step iii), wherein the wavelength of said focused electromagnetic radiation (C), preferably non-ionizing electromagnetic radiation (C), is in the range of 200 to 20000nm, preferably 300 to 18000nm, particularly preferably 350 to 16000nm.

Description

Method for locally coloring plastic parts using solid dyes in a color carrier layer

The invention relates to a method for the partial coloring, in particular color laser engraving, of plastic parts, in particular thermoplastic parts, very particularly thermoplastic parts comprising a layer structure, using a colored tape, to the resulting partial coloring, in particular color laser engraved plastic parts, in particular thermoplastic parts, and to the use of such colored plastic parts in security documents.

The possibility of colour laser engraving plastic parts is of interest to the whole plastic part manufacturing industry. Of interest here are color laser engraving of three-dimensionally shaped plastic parts, for example for the automotive industry. Thus, for example, colored symbols may be engraved for switches, trim pieces, etc. In this case, the plastic component comprising its surface protection lacquer can also be color laser engraved. The laser beam removes the paint layer while the dye migrates into the plastic surface at this location. Unprotected plastic surfaces may also be color laser engraved and subsequently painted to ensure a consistent glossy appearance of the plastic part and to provide protection against scratches and chemical damage. Such color symbols can hitherto be produced, for example, in a first production step by injection molding of plastics using a plurality of color components. In the second manufacturing step, the plastic part must be lacquered with a covering ink. In a third manufacturing step, the coloured layer must be laser engraved to expose the plastic surface underneath. Optionally, a protective lacquer may be applied in a fourth manufacturing step.

Alternatively, the transparent plastic film may be color engraved on the back surface, followed by post-injection molding with a thermoplastic (corresponding to the film insert molding process) to obtain a glossy or uniform appearance surface. Such a process is disclosed, for example, in example 1 of EP-A0691201.

In the market of security and/or valuable documents, in particular identification documents (identity documents), it is necessary to personalize these documents in color by means of a laser. In particular in the field of security and/or valuable documents, in particular identity documents, methods have been developed in recent years which enable the production of colour elements in these documents, which consist entirely or partly of polymeric films. These methods are described, for example, in WO-a 03/056507, EP-a 2752302 or JP-a 2012-011688, but are associated with considerable technical complexity. All methods include a printing process to achieve coloration. Such methods are also described, for example, in US 5,714,249 A1 or CN 1415481A.

WO-a 2017/167651 discloses a method of locally coloring, in particular colour laser engraving, plastic parts, in particular thermoplastic plastic parts, very particularly plastic films.

WO-a 03/056507 discloses a method of forming a colour image on a film by laser engraving. For this purpose, an ink that interacts with a laser of a specific wavelength should be printed over the entire surface on which the color image is subsequently formed. Once these colored pigments are exposed to the laser, the reaction manifests itself as bleaching of the colored pigments. If three types of pigments are used that interact at three different wavelengths, e.g. red, yellow, blue, a full color image can be produced. However, this method is particularly complex because three different laser sources with different wavelengths must be used and the ink must be printed onto the entire surface. This results in poor adhesion of the laminated film to the composite in the image area.

JP-a 2012-011689 discloses a method and apparatus for color laser printing on molded articles without damaging the substrate. In this method, an ink is applied to a molded article by ink jet, and then such ink is fixed to the molded article using a laser beam. Here too, the entire molding is initially sprayed with ink.

GB 2083726A describes a multicoloured donor element which allows ink to be transferred to a substrate by heating. U.S. Pat. No. 3,262 and WO97/38865 also describe laser absorbers in donor elements.

WO 2017167681 A1 describes the transfer of dye from a colouring bath onto a substrate.

However, the described method has the disadvantage of the resulting local coloring, in particular the sharpness and position accuracy of the resulting color laser engraving, in addition to the high resource strength.

It is therefore an object of the present invention to provide an improved method for locally coloring, in particular color laser engraving, plastic parts, preferably thermoplastic parts, very particularly thermoplastic parts comprising a layer structure, for example plastic films and/or film layer composites, wherein at least one disadvantage is at least partially ameliorated.

Another object of the invention is to make it possible to introduce fast, position-accurate, sharp and uniformly intense tinting, in particular colour laser engraving, into plastic parts. It is a further object of the present invention to provide a method of locally coloring plastic parts which allows locally coloring plastic parts which are sensitive to solvents, dyes or other additives.

Surprisingly, this object is achieved by the method according to the invention for the local coloring, in particular colour laser engraving, of plastic parts, preferably thermoplastic parts, very particularly preferably thermoplastic parts comprising a layer structure, said method comprising the steps of:

i) Providing a plastic part (a) having at least one surface;

ii) applying a coloured tape (B) containing at least one colorant, in particular a dye, on at least a portion of at least one surface of the plastic part (A) to obtain a surface of the plastic part (A) covered with coloured tape;

iii) Irradiating the plastic part (A) from ii) with focused electromagnetic radiation (C), preferably non-ionizing electromagnetic radiation (C), on at least a part of the surface of the plastic part (A) covered with the colored band,

wherein the local coloring is effected on the plastic part (A) substantially only at the locations irradiated in step iii),

wherein the wavelength range of the focused electromagnetic radiation (C), preferably the non-ionizing electromagnetic radiation (C), is 200 to 20000nm, preferably 300 to 18000nm, particularly preferably 350 to 16000nm.

In the present invention, "substantially" is understood to mean that only the locations illuminated in step iii) form color elements which appear clearly to the naked eye as visible color elements. The term "non-ionizing radiation" includes in the present invention electromagnetic waves whose energy is insufficient to ionize other atoms, because the energy of photons is lower than the bond energy of molecules or the ionization energy of atoms. This may also include light sources that in principle can generate energy in a specific wavelength range to ionize atoms, but are used in an intensity range where atoms cannot be ionized.

The provision of the plastic component (a) in step i) may be various provisions selected for this purpose by the person skilled in the art. Preferably, the provision is to lay, set, position or build the plastic part (a) on a surface, such as a table.

The application of the colored tape (B) to at least a portion of at least one surface of the plastic part (a) in step ii) to obtain a surface of the plastic part (a) covered with the colored tape (B) may be achieved in various ways selected for this purpose by the person skilled in the art. The application of the colored tape is preferably performed by creating a negative pressure between the colored tape and the plastic part. The negative pressure is preferably 10 to 500 mbar, more preferably 50 to 400 mbar below the standard pressure defined as 1013 mbar. Alternatively or additionally, an overpressure may be used, preferably at 0.01N/cm ² To 100N/cm ² The pressure of (a) presses the coloured ribbon (B) onto the plastic part (a).

The width of the colored tape (B) is preferably 5mm to 100cm, more preferably 10mm to 50cm, and still more preferably 1 to 20cm. The colored ribbon may have any desired length. The length of the colored ribbon is preferably 1m to 1000m, more preferably 10m to 500m, and still more preferably 50 to 100m.

The irradiation in step iii) may be carried out in various ways selected for this purpose by the person skilled in the art. Preferably, the non-ionizing electromagnetic radiation (C) is incident at an angle of 45 ° to 90 ° with respect to the ribbon plane of the colored ribbon (B), particularly preferably perpendicular to the colored ribbon (B) ±10°.

The energy transferred to the coloured band and the plastic component (a) during the irradiation in step iii) is preferably within the range that no material is transferred to or fused with the plastic component (a) other than the transfer of the colouring agent from the coloured band (B) to the plastic component (a).

The method according to the invention has in particular the following features: the local coloring of plastic parts, in particular thermoplastic parts, very particularly thermoplastic parts comprising a layer structure, takes place substantially at the location irradiated in step iii) of the method in a particularly high-intensity and high-sharpness coloring manner. Furthermore, the method according to the invention has the following features: the penetration depth of the colorants, especially dyes, into the plastic parts is large. The penetration depth of the local coloring is preferably from 10 to 500. Mu.m, more preferably from 20 to 300. Mu.m, particularly preferably from 50 to 200. Mu.m.

In a preferred embodiment of the method, in step iv), the colored band (B) is removed from the plastic part (a) after step iii). The removal of the coloured band (B) in step iv) may be carried out in various ways selected for this purpose by the person skilled in the art. The colored band (B) is preferably removed by eliminating the negative pressure optionally applied during the application of the colored band (B) in step ii). If no negative pressure is applied in step ii), the colored band (B) is removed manually or by raising the roll-to-roll device. Alternatively, a removal device, such as an air pressure or lever, may be employed to lift the colored ribbon (B) from the plastic part (a).

In a preferred embodiment, the focused electromagnetic radiation (C), preferably the non-ionizing electromagnetic radiation (C), is laser radiation having a wavelength of 500 to 15000nm, preferably 1000 to 10000nm, particularly preferably 1500 to 5000 nm.

In the non-irradiated areas, the remainder of the plastic part (a) has no or only very weak coloration. It is thus possible to color targeted areas of the plastic part in order to apply, for example, images, personalisation, logos, symbols or handwriting on such plastic parts by means of the method according to the invention. These cannot be removed from the plastic surface without destroying the plastic part. The method according to the invention is therefore particularly suitable in the field of manufacturing security documents and identification documents.

These color elements achieve extremely high resolutions of > 5000dpi, preferably > 6000dpi, particularly preferably 5000 to 10000dpi, especially when irradiated with laser radiation. The method according to the invention does not require high precision printing techniques nor does it require the use of different laser intensities, for example the emission of laser light of different wavelengths, as long as the irradiation in step iii) is performed with laser radiation. Furthermore, the method according to the invention is suitable for applying color elements to two-and/or three-dimensional plastic parts (a) and to thermoplastic parts (a) comprising a layer structure containing one or more thermoplastic layers.

A highly focused laser system can produce coherent color lines, which is a feature of security prints, with a width of preferably 10 μm. Heretofore, this has only been achieved by a process which requires complete wetting of the plastic part with the dye. By using a coloured tape which is brought into contact with the plastic part (a) only by laying, the remaining surface of the plastic part (a) is prevented from being coloured simultaneously and requiring subsequent washing off or removal of the dye with a solvent. This is particularly advantageous when the plastic part is sensitive to solvents, dyes or other additives used in conventional topical colouring.

In the case of three-dimensionally shaped plastic parts (a), the color tape can be laid directly on the plastic part (a) to be able to ensure color transfer.

In a preferred embodiment, the plastic part (A), preferably the thermoplastic part, very particularly preferably the thermoplastic comprising the layer structure contains a thermoplastic selected from polymers of ethylenically unsaturated monomers and/or polycondensates of difunctional reactive compounds and/or polyaddition products of difunctional reactive compounds. For certain applications, for example in the field of identification documents, it may be advantageous and therefore preferred to use transparent thermoplastics, preferably in the form of plastic films.

Particularly suitable thermoplastics are one or more polycarbonates or one or more copolycarbonates based on diphenols, one or more polyacrylates or copolyacrylates and one or more polymethacrylates or copolymethacrylates, for example and preferably polymethyl methacrylate or poly (meth) acrylate (PMMA), one or more styrene-containing polymers or copolymers, for exampleSuch as and preferably Polystyrene (PS), acrylonitrile-butadiene-styrene (ABS) or polystyrene-acrylonitrile (SAN), one or more thermoplastic polyurethanes and one or more polyolefins, for example and preferably polypropylene type or cycloolefin-based polyolefins (for exampleHoechst), one or more polycondensates or copolycondensates of terephthalic acid, for example and preferably poly-or copolyethylene terephthalate (PET or CoPET), glycol-modified PET (PETG), glycol-modified poly-or copolycyclohexanedimethanol terephthalate (PCTG) or poly-or copolybutylene terephthalate (PBT or cobt), polyamide (PA), one or more polycondensates or copolycondensates of naphthalene dicarboxylic acid, for example and preferably polyethylene naphthalate (PEN), one or more polycondensates or copolycondensates of at least one cycloalkyl dicarboxylic acid, for example and preferably polycyclohexane dimethanol cyclohexane dicarboxylic acid (PCCD), polysulphone (PSU), mixtures of at least two of the abovementioned or blends of at least two of the abovementioned.

Preferred thermoplastics are polycarbonates or copolycarbonates having an average molecular weight Mw of from 500 to 100000g/mol, preferably from 10000 to 80000g/mol, particularly preferably from 15000 to 40000 g/mol.

Particularly preferred thermoplastics are one or more polycarbonates or one or more copolycarbonates based on diphenols or blends comprising at least one polycarbonate or copolycarbonate. Very particular preference is given to blends comprising at least one polycarbonate or copolycarbonate and at least one polycondensate or copolycondensate of terephthalic acid, naphthalenedicarboxylic acid or cycloalkyldicarboxylic acid, preferably cyclohexanedicarboxylic acid.

Preferred thermoplastics are polycarbonates or copolycarbonates which in particular have an average molecular weight Mw of from 500 to 100000g/mol, preferably from 10000 to 80000g/mol, particularly preferably from 15000 to 40000g/mol, or a blend thereof with at least one polycondensate or copolycondensate of terephthalic acid having an average molecular weight Mw of from 10000 to 200000g/mol, preferably from 21000 to 120000 g/mol.

Suitable polycondensates or copolycondensates of terephthalic acid are polyalkylene terephthalates in a preferred embodiment of the invention. Suitable polyalkylene terephthalates are, for example, the reaction products of aromatic dicarboxylic acids or their reactive derivatives (e.g.dimethyl esters or anhydrides) and aliphatic, cycloaliphatic or araliphatic diols, and mixtures of these reaction products.

Preferred polyalkylene terephthalates may be prepared from terephthalic acid (or reactive derivatives thereof) and aliphatic or cycloaliphatic diols having from 2 to 10 carbon atoms by known methods (Kunststoff-Handbuch, vol. VIII, p. 695 and thereafter Karl-Hanser-Verlag, munchen 1973).

Preferred polyalkylene terephthalates contain at least 80 mole%, preferably 90 mole%, of terephthalic acid radicals, based on the dicarboxylic acid component, and at least 80 mole%, preferably at least 90 mole%, based on the diol component, of ethylene glycol radicals and/or butane-1, 4-diol radicals and/or cyclohexane-1, 4-dimethanol radicals.

Preferred polyalkylene terephthalates may contain up to 20 mole%, in addition to terephthalic acid radicals, of other aromatic dicarboxylic acids having 8 to 14 carbon atoms or aliphatic dicarboxylic acids having 4 to 12 carbon atoms, for example radicals of phthalic acid, isophthalic acid, naphthalene-2, 6-dicarboxylic acid, 4' -biphenyldicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, cyclohexanediacetic acid.

Preferred polyalkylene terephthalates may contain, in addition to ethylene glycol groups and/or butane-1, 4-diol groups, up to 80 mol% of radicals of other aliphatic diols having 3 to 12 carbon atoms or cycloaliphatic diols having 6 to 21 carbon atoms, such as propane-1, 3-diol, 2-ethylpropane-1, 3-diol, neopentyl glycol, penta-1, 5-diol, hexane-1, 6-diol, cyclohexane-1, 4-dimethanol, 3-methylpentan-2, 4-diol, 2, 4-trimethylpenta-1, 3-diol and 2-ethylhexyl-1, 6-diol, 2-diethylpropane-1, 3-diol the radicals of hexane-2, 5-diol, 1, 4-bis (. Beta. -hydroxyethoxy) benzene, 2-bis (4-hydroxycyclohexyl) propane, 2, 4-dihydroxy-1, 3-tetramethylcyclobutane, 2-bis (3- [ beta. -hydroxyethoxyphenyl) propane and 2, 2-bis (4-hydroxypropyloxyphenyl) propane (see DE-OS2507674, 2507776, 2715932).

The polyalkylene terephthalates may be branched by incorporating relatively small amounts of tri-or tetraols or tri-or tetracarboxylic acids as described, for example, in DE-OS1900270 and U.S. Pat. No. 3,92744. Examples of preferred branching agents are trimesic acid, trimellitic acid, trimethylolethane and trimethylolpropane and pentaerythritol. Preferably no more than 1 mole% of branching agent based on the acid component is used.

Particularly preferred are polyalkylene terephthalates which have been prepared solely from terephthalic acid and its reactive derivatives (e.g.its dialkyl esters) and ethylene glycol and/or butane-1, 4-diol and/or cyclohexane-1, 4-dimethanol radicals, and mixtures of these polyalkylene terephthalates.

Preferred polyalkylene terephthalates also include copolyesters made from at least two of the above-mentioned acid components and/or from at least two of the above-mentioned alcohol components; a particularly preferred copolyester is poly (ethylene glycol/but-1, 4-diol) terephthalate.

The polyalkylene terephthalates preferably used as components preferably have an intrinsic viscosity of approximately 0.4 to 1.5dl/g, preferably 0.5 to 1.3dl/g, in each case measured in phenol/o-dichlorobenzene (1:1 parts by weight) at 25 ℃.

In a particularly preferred embodiment of the invention, the blend of at least one polycarbonate or copolycarbonate with at least one polycondensate or copolycondensate of terephthalic acid is a blend of at least one polycarbonate or copolycarbonate with poly-or copolybutylene terephthalate or glycol-modified poly-or copolycyclohexanedimethanol terephthalate. Such a blend of polycarbonate or copolycarbonate with poly-or copoly-butylene terephthalate or glycol modified poly-or copoly-cyclohexanedimethanol terephthalate may preferably comprise 1 to 90 wt.% of polycarbonate or copolycarbonate and 99 to 10 wt.% of poly-or copoly-butylene terephthalate or glycol modified poly-or copoly-cyclohexanedimethanol terephthalate, preferably a blend comprising 1 to 90 wt.% of polycarbonate and 99 to 10 wt.% of poly-butylene terephthalate or glycol modified poly-cyclohexanedimethanol terephthalate, wherein the ratio amounts to 100 wt.%. Such a blend of polycarbonate or copolycarbonate with poly-or copoly-butylene terephthalate or glycol modified poly-or copoly-cyclohexanedimethanol terephthalate may more preferably comprise 20 to 85 weight percent of polycarbonate or copolycarbonate and 80 to 15 weight percent of poly-or copoly-butylene terephthalate or glycol modified poly-or copoly-cyclohexanedimethanol terephthalate, preferably a blend comprising 20 to 85 weight percent of polycarbonate and 80 to 15 weight percent of poly-butylene terephthalate or glycol modified poly-cyclohexanedimethanol terephthalate, wherein the ratio amounts to 100 weight percent. Such blends of polycarbonate or copolycarbonate with poly-or copoly-butylene terephthalate or glycol modified poly-or copoly-cyclohexanedimethanol terephthalate may most preferably comprise a blend of 35 to 80 weight percent of polycarbonate or copolycarbonate and 65 to 20 weight percent of poly-or copoly-butylene terephthalate or glycol modified poly-or copoly-cyclohexanedimethanol terephthalate, preferably comprising 35 to 80 weight percent of polycarbonate and 65 to 20 weight percent of poly-butylene terephthalate or glycol modified poly-cyclohexanedimethanol terephthalate, wherein the ratio amounts to 100 weight percent. Very particularly preferred embodiments may relate to blends of polycarbonate and glycol modified polycyclohexane dimethanol terephthalate having the compositions mentioned above.

Suitable polycarbonates or copolycarbonates include in particular aromatic polycarbonates or copolycarbonates. The polycarbonates or copolycarbonates may be linear or branched in a known manner.

These polycarbonates may be prepared in a known manner from diphenols, carbonic acid derivatives, optionally chain terminators and optionally branching agents. Details concerning the preparation of polycarbonates have been disclosed in many patent documents during about the last 40 years. Reference is made herein by way of example only to Schnell, "Chemistry and Physics of Polycarbonates", polymer Reviews, volume 9, interscience Publishers, new York, london, sydney 1964, reference D.Freitag, U.Grigo, P.R.M, muller, H.Nouvretne, BAYER AG, "Polycarbonates", encyclopedia of Polymer Science and Engineering, volume 11, version 2, 1988, pages 648-718, and finally reference Dres.U.Grigo, K.Kirchner and P.R. Muller, "Polycarbonate", becker/Braun, kunststoff-Handbuch, volume 3/1, polycarbonate, polyacetate, polyester, cellulose, carl Hanser Verlag M, munchen, wien 1992, pages 117-299.

Suitable diphenols may be, for example, dihydroxyaryl compounds of the formula (I)

HO-Z-OH(I)

Wherein Z is an aromatic group having 6 to 34 carbon atoms, which may contain one or more optionally substituted aromatic rings and aliphatic or alicyclic groups or alkylaryl groups or heteroatoms as bridging members.

Examples of suitable dihydroxyaryl compounds include: dihydroxybenzene, dihydroxybiphenyl, bis (hydroxyphenyl) alkanes, bis (hydroxyphenyl) cycloalkanes, bis (hydroxyphenyl) aryl compounds, bis (hydroxyphenyl) ethers, bis (hydroxyphenyl) ketones, bis (hydroxyphenyl) sulfides, bis (hydroxyphenyl) sulfones, bis (hydroxyphenyl) sulfoxides, 1' -bis (hydroxyphenyl) diisopropylbenzenes and compounds thereof alkylated on the ring and halogenated on the ring.

For example in DE-A3832396, FR-A1561518, H.Schnell, chemistry and Physics ofPolycarbonates, interscience Publishers, new York 1964, page 28 and thereafter; these and other suitable dihydroxyaryl compounds are described on page 102 and thereafter and D.G.Legrand, J.T.Bendler, handbook of Polycarbonate Science and Technology, marcel Dekker New York 2000, on page 72 and thereafter.

Preferred dihydroxyaryl compounds are, for example, resorcinol, 4' -dihydroxybiphenyl, bis (4-hydroxyphenyl) methane, bis (3, 5-dimethyl-4-hydroxyphenyl) methane, bis (4-hydroxyphenyl) diphenylmethane, 1-bis (4-hydroxyphenyl) -1-phenylethane 1, 1-bis (4-hydroxyphenyl) -1- (1-naphthyl) ethane, 1-bis (4-hydroxyphenyl) -1- (2-naphthyl) ethane, 2-bis (4-hydroxyphenyl) propane, 2-bis (3-methyl-4-hydroxyphenyl) propane 2, 2-bis (3, 5-dimethyl-4-hydroxyphenyl) propane, 2-bis (4-hydroxyphenyl) -1-phenylpropane, 2-bis (4-hydroxyphenyl) hexafluoropropane, 2, 4-bis (4-hydroxyphenyl) -2-methylbutane, 2, 4-bis (3, 5-dimethyl-4-hydroxyphenyl) -2-methylbutane, 1-bis (4-hydroxyphenyl) cyclohexane, 1-bis (3, 5-dimethyl-4-hydroxyphenyl) cyclohexane, 1-bis (4-hydroxyphenyl) -4-methylcyclohexane, 1, 3-bis [2- (4-hydroxyphenyl) -2-propyl ] benzene, 1,1' -bis (4-hydroxyphenyl) -3-diisopropylbenzene, 1' -bis (4-hydroxyphenyl) -4-diisopropylbenzene, 1, 3-bis [2- (3, 5-dimethyl-4-hydroxyphenyl) -2-propyl ] benzene, bis (4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, bis (3, 5-dimethyl-4-hydroxyphenyl) sulfone and 2,2', 3' -tetrahydro-3, 3' -tetramethyl-1, 1' -spirobi [ 1H-indene ] -5,5' -diol or dihydroxydiphenylcycloalkane of formula (Ia)

Wherein the method comprises the steps of

R ¹ And R is ² Independently of one another, represents hydrogen, halogen, preferably chlorine or bromine, C ₁ -C ₈ -alkyl, C ₅ -C ₆ Cycloalkyl, C ₆ -C ₁₀ -aryl, preferably phenyl, and C ₇ -C ₁₂ Aralkyl radicals, preferably phenyl-C ₁ -C ₄ Alkyl groups, in particular benzyl groups,

m is an integer from 4 to 7, preferably 4 or 5,

R ³ and R is ⁴ Can be selected independently for each X and independently of one another represent hydrogen or C ₁ -C ₆ -alkyl and

x represents a carbon atom and is represented by the formula,

provided that for at least one atom X, R ³ And R is ⁴ And simultaneously represents alkyl. Preferably, in formula (Ia), R is for one or two atoms X, especially for only one atom X ³ And R is ⁴ And simultaneously represents alkyl.

The radicals R used in formula (Ia) ³ And R is ⁴ Preferably alkyl is methyl. The X atom in the alpha position of the diphenyl-substituted carbon atom (C-1) is preferably not substituted by a dialkyl group, but alkyl disubstitution in the beta position of C-1 is preferred.

Particularly preferred dihydroxydiphenylcycloalkanes of the formula (Ia) are those having 5 and 6 ring carbon atoms X in the cycloaliphatic radical (m=4 or 5 in the formula (Ia)), for example diphenols of the formulae (Ia-1) to (Ia-3),

very particularly preferred dihydroxydiphenylcycloalkanes of the formula (Ia) are 1, 1-bis (4-hydroxyphenyl) -3, 5-trimethylcyclohexane (formula (Ia-1) where R ¹ And R is ² Is H).

Such polycarbonates can be prepared according to EP-A359953 from dihydroxydiphenyl cycloalkanes of the formula (Ia).

Particularly preferred dihydroxyaryl compounds are resorcinol, 4' -dihydroxybiphenyl, bis (4-hydroxyphenyl) diphenylmethane, 1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) -1- (1-naphthyl) ethane, bis (4-hydroxyphenyl) -1- (2-naphthyl) ethane, 2-bis (4-hydroxyphenyl) propane 2, 2-bis (3, 5-dimethyl-4-hydroxyphenyl) propane, 1-bis (4-hydroxyphenyl) cyclohexane, 1-bis (3, 5-dimethyl-4-hydroxyphenyl) cyclohexane, 1-bis (4-hydroxyphenyl) -3, 5-trimethylcyclohexane, 1' -bis (4-hydroxyphenyl) -3-diisopropylbenzene and 1,1' -bis (4-hydroxyphenyl) -4-diisopropylbenzene.

Very particularly preferred dihydroxyaryl compounds are 4,4' -dihydroxybiphenyl and 2, 2-bis (4-hydroxyphenyl) propane.

Either one dihydroxyaryl compound may be used to form the homopolycarbonate or a different dihydroxyaryl compound may be used to form the copolycarbonate. Either one dihydroxyaryl compound of formula (I) or (Ia) may be used to form the homopolycarbonate or a plurality of dihydroxyaryl compounds of formula (I) and/or (Ia) may be used to form the copolycarbonate. The various dihydroxyaryl compounds may be linked to one another either randomly or in blocks. In the case of copolycarbonates consisting of dihydroxyaryl compounds of the formulae (I) and (Ia), the molar ratio of dihydroxyaryl compound of the formula (Ia) to the other dihydroxyaryl compounds of the formula (I) optionally used together is preferably 99 mol% of (Ia) from 1 mol% to 2 mol% of (Ia) 98 mol% of (I), preferably 99 mol% of (Ia) from 1 mol% to 10 mol% of (Ia) 90 mol% of (I), in particular 99 mol% of (Ia) from 1 mol% to 30 mol% of (Ia) 70 mol% of (Ia).

Very particularly preferred copolycarbonates may be prepared using the dihydroxyaryl compounds 1, 1-bis (4-hydroxyphenyl) -3, 5-trimethylcyclohexane and 2, 2-bis (4-hydroxyphenyl) propane of the formulae (Ia) and (I).

Suitable carbonic acid derivatives can be, for example, diaryl carbonates of the formula (II)

Wherein the method comprises the steps of

R, R 'and R' are identical or different and independently of one another represent hydrogen, linear or branched C ₁ -C ₃₄ -alkyl, C ₇ -C ₃₄ -alkylaryl or C ₆ -C ₃₄ -aryl, R may additionally also represent-COO-R '"wherein R'" represents hydrogen, linear or branched C ₁ -C ₃₄ -alkyl, C ₇ -C ₃₄ -alkylaryl or C ₆ -C ₃₄ -aryl.

Preferred diaryl carbonates are, for example, diphenyl carbonate, methylphenyl-phenyl carbonate and di (methylphenyl) carbonate, 4-ethylphenyl-phenyl carbonate, di (4-ethylphenyl) carbonate, 4-n-propylphenyl-phenyl carbonate, di (4-n-propylphenyl) carbonate, 4-isopropylphenyl-phenyl carbonate, di (4-isopropylphenyl) carbonate, 4-n-butylphenyl-phenyl carbonate, di (4-n-butylphenyl) carbonate, 4-isobutylphenyl-phenyl carbonate, di (4-isobutylphenyl) carbonate, 4-tert-butylphenyl-phenyl carbonate, di (4-tert-butylphenyl) carbonate, 4-n-pentylphenyl-phenyl carbonate, di (4-n-pentylphenyl) carbonate, 4-n-hexylphenyl-phenyl carbonate, di (4-n-hexylphenyl) carbonate, 4-isooctylphenyl-phenyl carbonate, di (4-isooctylphenyl) carbonate, 4-n-nonylphenyl-phenyl carbonate, di (4-nonylphenyl-phenyl) carbonate, 4-cyclohexyl-phenyl-1-cyclohexyl-phenyl carbonate, 1-methylphenyl carbonate, bis [4- (1-methyl-1-phenylethyl) phenyl ] carbonate, biphenyl-4-yl-phenyl carbonate, bis (biphenyl-4-yl) phenyl carbonate, 4- (1-naphthyl) phenyl-phenyl carbonate, 4- (2-naphthyl) phenyl-phenyl carbonate, bis [4- (2-naphthyl) phenyl ] carbonate, 4-phenoxyphenyl-phenyl carbonate, bis (4-phenoxyphenyl) carbonate, 3-pentadecylphenyl-phenyl carbonate, bis (3-pentadecylphenyl) carbonate, 4-tritylphenyl-phenyl carbonate, bis (4-tritylphenyl) phenyl carbonate, methyl (salicylate) phenyl carbonate, methyl bis (salicylate) phenyl carbonate, ethyl bis (salicylate) phenyl carbonate, n-propyl (salicylate) phenyl carbonate, isopropyl (salicylate) phenyl carbonate, n-butyl (salicylate) phenyl (salicylate), isobutyl (salicylate) carbonate, isobutyl (salicylate) phenyl (salicylate) carbonate, isobutyl salicylate (salicylate) phenyl (salicylate) carbonate, di (t-butyl salicylate), di (phenyl salicylate) and di (benzyl salicylate) carbonates.

Particularly preferred diaryl compounds are diphenyl carbonate, 4-tert-butylphenyl-phenyl carbonate, di (4-tert-butylphenyl) carbonate, biphenyl-4-yl-phenyl carbonate, di (biphenyl-4-yl) carbonate, 4- (1-methyl-1-phenylethyl) phenyl-phenyl carbonate, di [4- (1-methyl-1-phenylethyl) phenyl ] carbonate and di (methyl salicylate) carbonate. Diphenyl carbonate is very particularly preferred.

Either one diaryl carbonate or a different diaryl carbonate may be used.

For controlling or modifying the end groups, it is also possible to use, for example, one or more monohydroxyaryl compounds which are not used for the preparation of the diaryl carbonate or carbonates used, as chain terminators. These may be those of the general formula (III)

Wherein the method comprises the steps of

R ^A Is straight-chain or branched C ₁ -C ₃₄ -alkyl, C ₇ -C ₃₄ -alkylaryl, C ₆ -C ₃₄ -aryl or-COO-R ^D Wherein R is ^D Is hydrogen, straight-chain or branched C ₁ -C ₃₄ -alkyl, C ₇ -C ₃₄ -alkylaryl or C ₆ -C ₃₄ -aryl and

R ^B 、R ^C identical or different and independently of one another represent hydrogen, straight-chain or branched C ₁ -C ₃₄ -alkyl, C ₇ -C ₃₄ -alkylaryl or C ₆ -C ₃₄ -aryl.

Such monohydroxyaryl compounds are, for example, 1-, 2-or 3-methylphenol, 2, 4-dimethylphenol, 4-ethylphenol, 4-n-propylphenol, 4-isopropylphenol, 4-n-butylphenol, 4-isobutylphenol, 4-tert-butylphenol, 4-n-pentylphenol, 4-n-hexylphenol, 4-isooctylphenol, 4-n-nonylphenol, 3-pentadecylphenol, 4-cyclohexylphenol, 4- (1-methyl-1-phenylethyl) phenol, 4-phenylphenol, 4-phenoxyphenol, 4- (1-naphthyl) phenol, 4- (2-naphthyl) phenol, 4-tritylphenol, methyl salicylate, ethyl salicylate, n-propyl salicylate, isopropyl salicylate, n-butyl salicylate, isobutyl salicylate, tert-butyl salicylate, phenyl salicylate and benzyl salicylate. Preferred are 4-tert-butylphenol, 4-isooctylphenol and 3-pentadecylphenol. Suitable branching agents may be compounds having three or more functional groups, preferably those having three or more hydroxyl groups.

Suitable compounds having three or more phenolic hydroxyl groups are, for example, phloroglucinol, 4, 6-dimethyl-2, 4, 6-tris (4-hydroxyphenyl) hept-2-ene, 4, 6-dimethyl-2, 4, 6-tris (4-hydroxyphenyl) heptane, 1,3, 5-tris (4-hydroxyphenyl) benzene, 1-tris (4-hydroxyphenyl) ethane, tris (4-hydroxyphenyl) phenyl methane, 2-bis (4, 4-bis (4-hydroxyphenyl) cyclohexyl) propane, 2, 4-bis (4-hydroxyphenyl isopropyl) phenol and tetrakis (4-hydroxyphenyl) methane.

Other suitable compounds having three or more functional groups are, for example, 2, 4-dihydroxybenzoic acid, trimesic acid/trimesic acid trichloride, cyanuric chloride and 3, 3-bis (3-methyl-4-hydroxyphenyl) -2-oxo-2, 3-indoline.

Preferred branching agents are 3, 3-bis (3-methyl-4-hydroxyphenyl) -2-oxo-2, 3-indoline and 1, 1-tris (4-hydroxyphenyl) ethane.

Plastic parts comprising the thermoplastic polymers described above may be extruded, co-extruded, cast, three-dimensionally printed and/or injection molded. The plastic part may also be a three-dimensional plastic part. It is also possible that the plastic part is a plastic part comprising a layer construction, such as a film, a film layer composite and/or a sheet, and combinations thereof, such as a post-injection molded film comprising the above-mentioned polymers. The plastic component is particularly preferably a film, film layer composite and/or sheet made by extrusion and/or coextrusion, comprising the above-mentioned polymers.

In a preferred embodiment, the plastic part (a), in particular the thermoplastic part, very particularly the thermoplastic part comprising the layer structure, comprises at least one additive having an absorption maximum in the wavelength range of the focused electromagnetic radiation used, preferably of the non-ionising electromagnetic radiation, or the plastic part (a) is coated in the form of a coating composition with at least one additive having an absorption maximum in the wavelength range of the focused electromagnetic radiation used, preferably of the non-ionising electromagnetic radiation.

In a preferred embodiment, the additive comprises at least one or more organic and/or inorganic IR absorbers.

Suitable additives include in principle all laser-sensitive additives, so-called laser marking additives, i.e. additives made of an absorber in the wavelength range of the radiation (C) used. The additive preferably comprises at least one or more organic and/or inorganic IR absorbers, preferably inorganic IR absorbers. Such additives and their use in molding compounds are described, for example, in WO-A2004/50766 and WO-A2004/50767 under the trade name Micabs ^TM Purchased from DSM corporation.

Suitable organic IR absorbers are, for example, compounds having as high an absorption as possible between 700nm and 2500nm (near infrared=nir). Suitable are, for example, infrared absorbers known from the literature, as described in M.Matsuoka, infrared Absorbing Dyes, plenum Press, new York,1990, according to the substance classes. Particularly suitable are infrared absorbers selected from the following classes of substances: azo, azomethine (Azomethin), methine (meth), anthraquinone, indanthrone, pyranthrone (pyronthron), flavanthrone (Flavanthron), benzanthrone, phthalocyanines, perylenes, dioxazines, thioindigoids, isoindolines, isoindolinones, quinacridones, pyrrolopyrroles or quinophthalones pigments, and metal complexes of azo, azomethine or methine dyes or metal salts of azo compounds. Among them, phthalocyanines and naphthalocyanines are very particularly suitable. Phthalocyanines and naphthalocyanines having bulky side groups are preferred due to their improved solubility in thermoplastics.

Suitable inorganic IR absorbers are, for example, mixed oxides of metals, such as the phosphorus-containing tin-copper mixed oxides described in WO-A2006/042714, those selected from the group consisting of borides and/or tungstates and mixtures thereof, preferably at least one or more IR absorbers selected from the group consisting of borides and/or tungstates and mixtures thereof, more preferably at least one or more IR absorbers selected from the group consisting of tungstates.

Suitable inorganic IR absorbers selected from borides include, for example, M _x B _y Compounds of the type (m= La, ce, pr, nd, tb, dy, ho, Y, sm, eu, er, tm, yb, lu, sr, ti, zr, hf, V, ta, cr, mo, W and Ca; and x and y are integers from 1 to 6), in which lanthanum hexaboride (LaB ₆ ) Praseodymium boride (PrB) ₆ ) Neodymium boride (NdB) ₆ ) Cerium boride (CeB) ₆ ) Terbium boride (TbB) ₆ ) Dysprosium boride (DyB) ₆ ) Holmium boride (HoB) ₆ ) Yttrium Boride (YB) ₆ ) Samarium boride (SmB) ₆ ) Europium boride (EuB) ₆ ) Erbium boride (ErB) ₆ ) Thulium boride (TmB ₆ ) Ytterbium boride (YbB) ₆ ) Lutetium boride (LuB) ₆ ) Strontium boride (SrB) ₆ ) Calcium boride (CaB) ₆ ) Titanium boride (TiB) ₂ ) Zirconium boride (ZrB) ₂ ) Hafnium boride (HfB) ₂ ) Vanadium Boride (VB) ₂ ) Tantalum boride (TaB) ₂ ) Chromium boride (CrB and CrB) ₂ ) Molybdenum boride (MoB) ₂ 、Mo ₂ B ₅ And MoB), tungsten boride (W) ₂ B ₅ ) Or a combination of these borides.

Suitable inorganic IR absorbers from the group of tungstates also include, for example, those from the group W _y O _z (w=tungsten, o=oxygen; z/y=2.20-2.99) and/or M _x W _y O _z Those of tungsten compounds of the type (m= H, he, alkali metals, alkaline earth metals, rare earth metals, mg, zr, cr, mn, fe, ru, co, rh, ir, ni, pd, pt, cu, ag, au, zn, cd, al, ga, in, tl, si, ge, sn, pb, sb, B, F, P, S, se, br, te, ti, nb, V, mo, ta, re, be, hf, os, bi; x/y=0.001 to 1.000; z/y=2.2 to 3.0), among which the elements preferred as M are H, cs, rb, K, tl, in, ba, li, ca, sr, fe and Sn, of which Cs is very particularly preferred. Especially preferred is Ba _0.33 WO ₃ 、Tl _0.33 WO ₃ 、K _0.33 WO ₃ 、Rb _0.33 WO ₃ 、Cs _0.33 WO ₃ 、Na _0.33 WO ₃ 、Na _0.75 WO ₃ And mixtures thereof. In a particular embodiment of the invention, it is very particularly preferred to use Cs alone _0.33 WO ₃ As inorganic IR absorbers. Also preferred are Cs/W ratios of 0.20 and 0.25.

In the case of inorganic IR absorbers, if the process according to the invention is to be carried out on plastic parts having a radiation transmission of the selected radiation, determined by the UV-VIS-NIR-MIR method according to DIN EN ISO/IEC 17025, of from greater than or equal to 10% to less than or equal to 99%, preferably from greater than or equal to 30% to less than or equal to 95%, particularly preferably from greater than or equal to 40% to less than or equal to 93%, tungstate is preferred to boride due to its low intrinsic coloration.

For the preparation of such tungstates, for example tungsten trioxide, tungsten dioxide, tungsten oxide hydrate, tungsten hexachloride, ammonium tungstate or tungstic acid and optionally other salts containing the element M, for example cesium carbonate, are mixed in a particular stoichiometric ratio to give a composition of the formula M _x W _y O _z The molar ratios of the components are given. This mixture is then subjected to a reducing atmosphere, for example an argon-hydrogen atmosphere, at a temperature of from 100 ℃ to 850 DEG CTreating, and heat treating the powder at 550-1200 deg.c in inert atmosphere. To prepare the inorganic IR absorber nanoparticles of the present invention, the IR absorber can be mixed with a dispersant as described below and other organic solvents, such as toluene, benzene or similar aromatic hydrocarbons, and milled in a suitable mill, such as a ball mill, with the addition of zirconia (e.g., 0.3 mm in diameter) to produce the desired particle size distribution. The nanoparticles are obtained in the form of a dispersion. Further dispersant may optionally be added after milling. The solvent was removed at elevated temperature and reduced pressure. Preferred are nanoparticles having an average particle size of less than 200nm, more preferably less than 100 nm. The particle size of the particles can be determined by means of Transmission Electron Microscopy (TEM). Such measurement of IR absorber nanoparticles is described, for example, in Adachi et al, j.am.Ceram.Soc.2008,91, 2897-2902.

The preparation of preferred tungstates is described more precisely, for example in EP-a 1801815, and said tungstates are available, for example, from Sumimoto Metal minigco, ltd.

For example, in order to be used in plastic parts (A) comprising transparent thermoplastics having a radiation transmission of the selected radiation, determined by the UV-VIS-NIR-MIR method according to DIN EN ISO/IEC 17025, of from greater than or equal to 10% to less than or equal to 99%, preferably from greater than or equal to 30% to less than or equal to 95%, particularly preferably from greater than or equal to 40% to less than or equal to 93%, the particles thus obtained are dispersed in an organic matrix, for example an acrylate, and optionally milled in a mill as described above using suitable auxiliaries, for example zirconium dioxide and optionally using organic solvents, for example toluene, benzene or similar hydrocarbons.

Suitable polymer-based dispersants are in particular dispersants with high transmittance, such as polyacrylates, polyurethanes, polyethers, polyesters or polyester polyurethanes, and polymers derived therefrom.

Preferred dispersants are polyacrylates, polyethers and polyester-based polymers, with particularly preferred dispersants having high temperature stability being polyacrylates, such as polymethyl methacrylate and polyesters. Mixtures of these polymers or acrylate-based copolymers may also be used. The preparation of dispersion aids and tungstate dispersions of this type is described, for example, in JP 2008214596 and in Adachi et al J.Am.Ceram.Soc.2007, 904059-4061.

Dispersants based on polyacrylates are particularly suitable. Such suitable dispersants may be described, for example, under the trade name EFKA ^TM For example EFKA ^TM 4500 and EFKA ^TM 4530 is obtained from Ciba Specialty Chemicals. Polyester-containing dispersants are likewise suitable. They can be obtained, for example, under the trade name Solsperse ^TM For example Solsperse ^TM 22000. 24000SC, 26000, 27000 are available from Avecia. Polyether-containing dispersants are also known, for example under the trade name Disparlon from the company Kusumoto Chemicals ^TM DA234 and DA325. Polyurethane-based systems are also suitable. Polyurethane-based systems may be described under the trade name EFKA ^TM 4046、EFKA ^TM 4047 is obtained from Ciba Specialty Chemicals. Texaphor ^TM P60 and P63 are the corresponding trade names for Cognis.

The amount of IR absorber in the dispersant may be from 0.2 to 50.0 wt%, preferably from 1.0 to 40.0 wt%, more preferably from 5.0 to 35.0 wt%, most preferably from 10.0 to 30.0 wt%, based on the dispersion of inorganic IR absorber used according to the invention. The total composition of the ready-to-use IR absorber formulation may contain, in addition to the IR absorber pure material and the dispersant, other adjuvants such as zirconium dioxide, and residual solvents such as toluene, benzene or similar aromatic hydrocarbons.

The amount of inorganic IR absorbers according to the invention, particularly preferably those selected from tungstates, in the polymer composition of the plastic part is not limited. However, the inorganic IR absorbers, especially tungstates, can generally be used in amounts of from 0.7% by weight to 4.5% by weight, preferably from 0.6% by weight to 2% by weight, more preferably from 0.7% by weight to 1.5% by weight, calculated as the solid portion of the inorganic R absorber in the total polymer composition.

In this context, the solid portion of an inorganic IR absorber, in particular a tungstate, refers to an inorganic IR absorber, in particular a tungstate, as a pure substance, not as a pure substance-containing dispersion, suspension or other article, wherein the following description of the content of IR additives, in particular the content of tungstate, is always based on such solid portion, unless explicitly indicated otherwise.

In another embodiment, in addition to the tungstate as IR absorber, other IR absorbers may optionally be used, wherein the proportions in such mixtures are each lower than the proportions of the tungstate described above. In the case of mixtures, preference is given to compositions containing from 2 to 5 (inclusive) and particularly preferably 2 or 3 different IR absorbers. The other IR absorbers are preferably selected from borides and tin oxides, more preferably contain LaB ₆ Or antimony doped tin oxide, or indium tin oxide.

Such IR absorber mixtures are mainly used in applications where a component intrinsic coloration of Δe of at most 20, preferably at most 15, compared to plastic components without IR absorber is acceptable.

The at least one additive having an absorption maximum in the wavelength range of the focused electromagnetic radiation used, preferably non-ionizing electromagnetic radiation, may be contained in the plastic part.

In a preferred embodiment, the coloured band (B) comprises at least one colorant, preferably at least one dye, or a mixture thereof, which is separable from the coloured band by heating. The colorant may be various materials opaque in the visible wavelength range, which are incorporated into the colored tape (B) such that it separates therefrom upon heating. The colorant is preferably selected from the group consisting of dyes, colored pigments, colored minerals, or a mixture of at least two thereof.

In a preferred embodiment of the process, the coloured band (B) comprises a dye, particularly preferably at least one dye selected from the group of solvent dyes and/or disperse dyes classified according to the Colour Index (Colour Index) or a mixture of these dyes.

The dye index (CI) of the uk dyeing worker society (Society ofDyers and Colourists) and the american society of textile chemists and colorists (American Association of Textile Chemists and Colorists) clearly characterizes all colorants by class name and numbering of chemical composition or chemical structure.

Dyes selected from solvent dyes classified according to the dye indexMay be, for example, the so-called macroex from Lanxess AG, germany ^TM A dye. Examples include Macrolex ^TM Blue 3R, macrolex ^TM Red H, macrolex ^TM Yellow 6G (solvent yellow 179 according to CI), macrolex ^TM Purplish red R (disperse Violet 31 according to CI), macrolex ^TM Orange R (solvent orange 107 according to CI) or a mixture of these dyes.

Dyes selected from disperse dyes classified according to the dye index may be, for example, diazo, diphenylamine and anthraquinone compounds, acetate dyes, disperse dyes and/or disperse sol dyes and include disperse blue #3, disperse blue #14, disperse yellow #3, disperse red #134 and disperse red #7. The classification and designation of The above dyes is in accordance with The "The color Index", 3 rd edition, united kingdom dyeing workers society and United states textile chemists and Council of dyeing companies (1971). Dyes are very often used as single dye ingredients or as components of a mixture, depending on the desired color. The term dye as used herein also includes dye mixtures.

Suitable dyes include water insoluble diazonium, diphenylamine and anthraquinone compounds. Particularly suitable are acetate dyes, disperse dyes and disperse sol dyes as disclosed in Colour Index, 3 rd edition, volume 2, the institute of dyeing workers, 1971, pages 2479 and 2187-2743.

Preferred disperse dyes include Dystar's Palanil blue E-R150 (anthraquinone/disperse blue), DIANIX orange E-3RN (azo dye/Cl disperse orange 25) and Macrolex as described above ^TM The dye acts as a solvent dye.

The colored ribbon (B) preferably comprises a dye and/or a dye mixture selected from disperse dyes classified according to the dye index, very particularly a dye selected from azo, diphenylamine and anthraquinone compounds.

The color band (B) also preferably comprises dyes and/or dye mixtures selected from the solvent dyes classified according to the dye index, very particularly preferably Macrolex ^TM Dyes and/or dye mixtures of dyes.

The colorant, preferably a dye, may be incorporated into the colored tape (B) using a solvent and/or a dispersant. The solvent and/or dispersant used may be a polymeric material, such as a polyester. Preferred are the polymeric materials described in the dispersant for the additive.

The irradiation of the plastic component (A) in step ii) is carried out with focused electromagnetic radiation, preferably non-ionising electromagnetic radiation, wherein the wavelength range of the focused electromagnetic radiation, preferably non-ionising electromagnetic radiation, is selected such that the pigmented tape (B) has a radiation transmission of the selected radiation, determined by the UV-VIS-NIR-MIR method according to DIN EN ISO/IEC 17025-2018-03, of from more than or equal to 2% to less than or equal to 99%, preferably from more than or equal to 5% to less than or equal to 95%, particularly preferably from more than or equal to 10% to less than or equal to 93%.

In a preferred embodiment of the method, the colored tape (B) comprises:

a) The polymer carrier is a polymer carrier comprising a polymer,

b) At least one colorant, preferably at least one dye, particularly preferably at least one dye selected from solvent dyes and/or disperse dyes classified according to the dye index, or mixtures of the above-mentioned dyes.

The polymeric support may be any support containing a polymer suitable for use with preferably non-ionising electromagnetic radiation, in particular a polymeric support which does not melt during irradiation in step iii) and which is as transparent as possible. Preferred polymers for constructing the polymeric support are polymers selected from polyesters.

In a preferred embodiment of the method, the plastic part (a) comprises a layer construction, wherein the layer construction comprises at least one thermoplastic layer.

In a preferred embodiment of the method, the layer structure comprises at least one layer comprising at least one thermoplastic and at least one further layer comprising at least one thermoplastic and at least one black pigment, preferably carbon black.

In a preferred embodiment, the irradiation in step iii) is carried out with a pulsed laser, preferably with pulses having a duration of from 1ns to 10000ns, preferably from 5ns to 5000ns, particularly preferably from 10ns to 1000ns and an energy of preferably from 0.1J to 10kJ, particularly preferably from 0.2J to 8kJ, very particularly preferably from 0.5J to 5 kJ. The irradiation in step iii) is particularly preferably carried out with a pulsed laser having pulses of duration from 1ns to 10000ns and energy from 0.1J to 10 kJ. The irradiation in step iii) is preferably carried out with a pulsed laser having pulses with a duration of 5ns to 5000ns and an energy of 0.2J to 8 kJ. The irradiation in step iii) is further preferably carried out with a pulsed laser having pulses with a duration of 10ns to 1000ns and an energy of 0.5J to 5 kJ.

The laser irradiation is preferably performed in continuous wave operation (CW laser). It is particularly preferred to use pulsed laser radiation to irradiate the plastic part. In this case, a laser pulse duration of a fraction of a second is sufficient to achieve a coloration of the plastic part at the laser irradiation site. Preferably 10 is used ^-18 To 10 ^-1 Pulse duration of seconds, particularly preferably 10 ^-9 To 10 ^-2 Pulse duration of seconds, very particularly preferably 10 ^-6 To 10 ^-3 Pulse duration of seconds.

By varying the power of the laser beam used for irradiation in step ii), the intensity of the coloration at the laser irradiation location can be influenced according to the requirements of the desired application. The higher the laser power used, the more intense the coloration at the laser irradiation site of the plastic part. A sufficiently good colour engraving can be achieved by a medium power range of the 7.5 watt marking laser. A significantly higher power and thus also a stronger coloration in the plastic part can be achieved in pulsed operation.

By varying the power of the laser beam used for irradiation in step ii), it is possible to control whether carbonization of the plastic surface and thus grey or black engraving is to be achieved or whether engraving is to be performed in a colour, for example blue, magenta, yellow. The method according to the invention preferably uses a NdYAG laser (neodymium-doped yttrium-aluminum-garnet laser) and uses it to engrave plastic parts made of polycarbonate. At pulse frequencies of up to 25kHz, grey engraving in plastic parts made of polycarbonate can still be achieved. At higher frequencies (> 25 kHz) and thus lower energy densities, the energy of the laser is no longer sufficient to achieve black or grey coloration, but blue, magenta, yellow engraving can still be performed at these energy densities.

Preferably, a NdYAG laser (neodymium doped yttrium-aluminum-stone) is used in the method according to the inventionGarnet laser). The energy input of radiation C) in step iii) can be varied by pulses of different duration at the same laser power. The shorter the pulse, the higher the pulse peak energy. At pulse lengths of 1ns to 10000ns, a pulse peak of 10kJ can be achieved. However, the colour laser engraving of plastic parts can also be performed using a laser type suitable for plastic engraving and welding. For example, CO may also be used ₂ A laser. This may be preferred for achieving blue, magenta, yellow engraving.

The color concentration of the colored band can also affect the intensity of the localized coloration of the plastic part after irradiation. Preferably, the concentration of the colorant, preferably dye, is from 0.01% to 25% by weight, preferably from 0.1% to 20% by weight, particularly preferably from 0.2% to 18% by weight, based on the total weight of the colored tape.

A preferred embodiment of the method according to the invention uses molded articles made of plastic, which are made in an injection molding apparatus according to known methods, for example according to in-mold decoration (IMD), film insert molding or high pressure molding (HPF) methods.

In a further preferred embodiment of the method according to the invention, the plastic component is a layer structure comprising at least one thermoplastic layer selected from the group consisting of polymers of ethylenically unsaturated monomers and/or polycondensates of difunctional reactive compounds, preferably one or more polycarbonates or one or more copolycarbonates based on diphenols, one or more polyacrylates or copolyacrylates and one or more polymethacrylates or copolymethacrylates, one or more styrene-containing polymers or copolymers, one or more polyurethanes and one or more polyolefins, one or more polycondensates or copolycondensates of terephthalic acid, one or more polycondensates or copolycondensates of naphthalene dicarboxylic acid, one or more polycondensates or copolycarbonates of at least one cycloalkyl dicarboxylic acid, or mixtures thereof, particularly preferably one or more polycarbonates or one or more copolycarbonates based on diphenols or blends containing at least one polycarbonate or copolycarbonate.

Very particular preference is given to the at least one layer comprising at least one thermoplastic being a film. Such films preferably have a layer thickness of from 1 μm to 1000 μm, preferably from 5 μm to 800 μm, very particularly preferably from 10 μm to 500 μm.

For the avoidance of repetition, reference is made to the description of the thermoplastic hereinabove with respect to preferred embodiments, materials, compositions and additives.

The layer structure preferably comprises at least one layer comprising at least one thermoplastic as described above and at least one further layer comprising at least one thermoplastic as described above and at least one laser-sensitive additive, preferably a black pigment, particularly preferably carbon black. Such layer constructions are known from WO-a 2010/089035, for example, and are suitable for black and white laser engraving, in particular for personalized laser engraving of security documents, very particularly identification documents.

The layer arrangement preferably has at least one layer containing at least one thermoplastic and at least one filler. The filler is preferably at least one coloring pigment and/or at least one other filler for producing translucency of the filler layer, particularly preferably a white pigment, very particularly preferably titanium dioxide, zirconium dioxide or barium sulfate, in a preferred embodiment titanium dioxide.

Filling a layer containing at least one thermoplastic with at least one such filler improves the visibility of the introduced text or image or images, thus also further enhancing the perception of improved sharpness and resolution. Such layer constructions are known from WO-a 2010/089035 and are described in detail therein.

The at least one thermoplastic layer preferably contains at least one additive which has an absorption maximum in the wavelength range of the focused electromagnetic radiation used, preferably non-ionizing electromagnetic radiation, and wherein such at least one thermoplastic layer has a radiation transmission, measured by the UV-VIS-NIR-MIR method according to DIN EN ISO/IEC 17025, of from greater than or equal to 10% to less than or equal to 99%, preferably from greater than or equal to 30% to less than or equal to 95%, particularly preferably from greater than or equal to 40% to less than or equal to 93%, of the selected radiation, preferably an inorganic IR absorber, particularly preferably an inorganic IR absorber selected from tungstates. Such a layer preferably forms an outer layer of the layer structure, which is finally also colour laser engraved.

The layer arrangement preferably comprises at least one thermoplastic outer layer which contains at least one additive having an absorption maximum in the wavelength range of the focused electromagnetic radiation used, preferably non-ionizing electromagnetic radiation, and wherein such at least one thermoplastic layer has a radiation transmission, measured by the UV-VIS-NIR-MIR method according to DIN EN ISO/IEC 17025, of from 10% to 99%, preferably from 30% to 95%, particularly preferably from 40% to 93%, for the selected radiation, preferably an inorganic IR absorber, particularly preferably an inorganic IR absorber selected from tungstates, and further layers which contain at least one thermoplastic and at least one laser-sensitive additive, preferably a black pigment, particularly preferably carbon black, and optionally further thermoplastic layers comprising a filler, preferably a white pigment, particularly preferably titanium dioxide, zirconium dioxide or barium sulfate, very particularly preferably titanium dioxide.

This embodiment enables, for example, a combination of color laser engraving and black laser engraving according to the invention. For this purpose, the plastic component (a) comprising the above-described layer structure can be irradiated with C) before or after step i) or step ii) in the absence of a color band (B), as in step iii). The same radiation (C) may be used ideally for this further irradiation. By irradiating with (C) in the absence of a color stripe (B), a black engraving can be applied to the surface at the desired location, preferably in the transparent and/or white layer of the layer construction underneath it. The high laser reactivity of these layer structures results in blackening at the laser irradiation site without laser engraving using the colored band (B). If the layer structure is in contact with the colored band (B), the colored band (B) reduces the intensity of the laser beam so that coloring is effected only at the irradiated position, but does not cause blackening of the surface of the layer structure.

The thickness of the coloured layer is preferably precisely adjusted during the whole process and preferably kept constant during the whole process in order to be able to obtain a uniform laser engraving. The thickness of the colored layer is preferably from 0.001mm to 10mm, particularly preferably from 0.005mm to 5mm, very particularly preferably from 0.01mm to 1mm.

Another subject of the invention is a plastic part or plastic article obtainable by the process of the invention.

In a preferred embodiment of the plastic component (a), the component is a security document and/or a value document, very particularly preferably an identification document. In particular, the security document personalized or colour engraved by the method of the invention is characterized by a high security against forgery of the personalized or colour engraved information applied. By the method of the invention, the color personalization of the blank document can be performed in a decentralized and anti-counterfeiting manner. It is also possible to generate colored tactile laser engraving.

Example 1 (according to the invention)

First of all a plastic part (a) in the form of a laminated plastic film composite (a) (hereinafter referred to as laminate (a)) made of two different polycarbonate films, namely film 1) and film 2) is prepared and provided according to step i) of the inventive method. Then, on the laminate (a), a colored tape is laid on one of the surfaces of the laminate (a) according to step ii) and colored using a laser according to step iii).

Step i) providing a plastic part (a) in the form of a laminate (a):

membrane 1) is Makrofol from Covestro Deutschland AG company with a thickness of 100. Mu.m ^TM A polycarbonate film having the following composition:

94.69% by weight of Makrofol ^TM 3108 polycarbonate film from Covestro Deutschland AG Corp

0.75% by weight of YMDS 874IR absorber from Sumitomo company

4.5 wt% Makrolon ^TM 3108 powder from Covestro Deutschland AG company

0.006% by weight (60 ppm) of lamp black 101 (carbon black from Evonik-Degussa GmbH) with an average particle size of 95nm (according to manufacturer data)

Membrane 2) is Makrofol from Covestro Deutschland AG company with a thickness of 500. Mu.m ^TM ID4-4 opaque white polycarbonate.

Lamination of films 1) and 2) was performed as follows to produce a laminate (a).

First, the films 1) and 2) were stacked as follows:

film 1)	100μm
		Film 2)	500μm
Film 1)	100μm

The film stack was placed in a model 50/100 laminator from Burckle. The films were laminated using the following laminator setup so that both surfaces of laminate (a) were formed from film 1):

heating zone: the temperature was 190℃and the duration was 8 minutes, the pressure was 60N/cm ²

And (3) a cooling area: the temperature is 38 ℃ and the duration is 10 minutes, and the pressure is 100N/cm ²

The laminate (a) from step i) was placed on the workpiece carrier of a FobaD84S laser apparatus such that one surface of the laminate (a) was on the workpiece carrier and the opposite surface was facing the laser. The laser was a diode pumped NdYAG laser that emitted at 1064nm at about 60 watts.

Step ii) applying a coloured tape:

the coloured tape is then placed on the laminate with the dye coated side in contact with one of the films 1) of laminate (a). A CY-35K-75D model colored tape from DNP co., ltd. The colored tape is fixed to the edge region of the laminate (a) and negative pressure is generated between the laminate (a) and the colored tape using air suction to avoid the formation of air inclusions between the laminate (a) and the colored tape. A slight negative pressure of about 100 mbar is maintained throughout the duration of the irradiation in step iii).

Step iii) irradiation:

the focus of the NdYAG laser is set at a position on the surface of the colored tape that is in contact with the laminate (a). For laser engraving, a laser frequency of 30kHz and a current intensity of 28 amps were set. The traveling speed of the laser light was 100mm/s.

Laser processing is performed through the blue region of the colored tape.

Letters, numbers and symbols are engraved on the laminate. These engravings have intense coloration. Furthermore, laser engraving is also designed in a tactile manner. These engravings are sufficiently raised to be able to be touched and clearly visible.

The laser engraving is repeated a second time, but without the use of a colored band. The laminate surface is directly subjected to laser irradiation. Laser processing uses varying parameters, particularly 5kHz and 32 amps. The engraved letters, numbers and symbols thus appear dark black.

The penetration depth of the dye into the laminate (a) was determined.

Strips of about 20 μm in thickness were cut from a section of laminate (a) using a model HM 355S microtome from Thermo Scientific company. When the cross section was observed under transmitted light using a microscope at 100 times magnification, it was found that the film 1) was completely colored at a thickness of 100 μm. The coloration is more intense in the outer region of the irradiated film 1), but it reaches the inner boundary line with the adjacent film 2), i.e. the depth of 100 μm.

EXAMPLE 2) laser engraving in liquid (not according to the invention)

For comparison, a plastic part (a) in the form of a laminate plastic film laminate (a) (hereinafter referred to as laminate (a)) identical to that described in example 1) was colored by a coloring bath as described in the prior art in patent application WO-a 2017/167651.

The laminate (a) manufactured and constructed as described in step i) of example 1) was immersed to a depth of 0.5mm immersion in a colouring bath. The immersion depth is understood to be the path or penetration depth of the radiation C) used into the coloring bath up to the surface of the plastic part (A) onto which the partial coloring is to be applied.

For this purpose the following colouring bath compositions were used:

69.31% by weight of water

0.99 wt%Blue 3R (dye, lanxess AG Germany)

19.8% by weight of Ethylene Glycol Butyl Ether (EGBE), (solvent, the Dow Chemical Company)

9.9% by weight of diethylene glycol (DEG), (leveling agent, merck KGaA)

The coloring bath with laminate (a) was placed on a work piece carrier of a Foba D84S laser apparatus with the NdYAG laser used in example 1.

Generating laser engraving:

the focus of the laser is set on the surface of the laminate (a). For laser engraving, a frequency of 30kHz and a current intensity of 28 amps were set. The traveling speed of the laser light was 100mm/s.

Letters, numbers and symbols are engraved on the laminate. These engravings have intense coloration. Furthermore, laser engraving is also designed in a tactile manner. These engravings are sufficiently raised to be able to be touched and clearly visible.

The laser engraving is then repeated a second time, but without the use of a coloring liquid. The laminate surface is directly subjected to laser irradiation. Laser processing uses varying parameters, particularly 5kHz and 32 amps. The engraved letters, numbers and symbols thus appear dark black.

The penetration depth of the dye into the laminate was determined.

Strips of approximately 20 μm in thickness were cut from a cross section of the laminate using a model HM 355S microtome from Thermo Scientific company. When the cross section was observed under transmitted light using a microscope at 100 times magnification, a film 1) having a thickness of 100 μm was found to be colored. The penetration depth of the coloration can only be found in the outer region of the membrane 1) at a depth of at most 25 μm.

Claims (15)

1. A method of locally coloring a plastic part comprising the steps of:

i) Providing a plastic part (a) having at least one surface;

ii) applying a coloured tape comprising at least one colorant to at least a portion of at least one surface of the plastic part (a) to obtain a surface of the plastic part (a) covered with coloured tape;

iii) Irradiating the plastic part (A) from ii) with focused electromagnetic radiation (C), preferably non-ionizing electromagnetic radiation (C), on at least a part of the surface of the plastic part (A) covered with the colored band,

wherein the local coloring is effected on the plastic part (A) substantially only at the locations irradiated in step iii),

wherein the wavelength range of the focused electromagnetic radiation (C), preferably the non-ionizing electromagnetic radiation (C), is 200 to 20000nm, preferably 300 to 18000nm, particularly preferably 350 to 16000nm.

2. A method according to claim 1, wherein in step iv) the coloured ribbon is removed from the plastic part (a) after step iii).

3. The method according to any one of claims 1 or 2, wherein the focused electromagnetic radiation (C), preferably non-ionizing electromagnetic radiation (C), is laser radiation having a wavelength of 500 to 15000nm, preferably 1000 to 10000nm, particularly preferably 1500 to 5000 nm.

4. A method according to claim 1, 2 or 3, wherein the plastic part (a) contains a thermoplastic selected from polymers of ethylenically unsaturated monomers and/or polycondensates of difunctional reactive compounds and/or polyaddition products of difunctional reactive compounds.

5. The method according to claims 1 to 4, wherein the plastic part (a) comprises at least one additive having an absorption maximum in the wavelength range of the focused electromagnetic radiation used, preferably non-ionizing electromagnetic radiation, or wherein the plastic part is coated with at least one additive having an absorption maximum in the wavelength range of the focused electromagnetic radiation used, preferably non-ionizing electromagnetic radiation, in the form of a coating composition.

6. The method of claim 5, wherein the additive comprises at least one or more organic and/or inorganic IR absorbers.

7. The method according to claims 1 to 6, wherein the colored ribbon (B) comprises at least one colorant, preferably at least one dye, or a mixture thereof, which is separable from the colored ribbon by heating.

8. The method according to claims 1 to 7, wherein the colored ribbon (B) comprises at least one dye selected from solvent dyes and/or disperse dyes classified according to the dye index or a mixture of these dyes.

9. The method according to claims 1 to 8, wherein the colouring tape (B) comprises:

a) The polymer carrier is a polymer carrier comprising a polymer,

b) At least one colorant, preferably at least one dye, particularly preferably at least one dye selected from solvent dyes and/or disperse dyes classified according to the dye index, or mixtures of the above-mentioned dyes.

10. The method according to claims 1 to 9, wherein the plastic part (a) comprises a layer construction, wherein the layer construction comprises at least one thermoplastic layer.

11. The method according to claim 10, wherein the layer construction comprises at least one layer comprising at least one thermoplastic and at least one further layer comprising at least one thermoplastic and at least one black pigment, preferably carbon black.

12. The method according to any one of claims 1 to 11, wherein the irradiation in step iii) is performed with a pulsed laser, preferably with pulses having a duration of 1ns to 10000ns and an energy of preferably 0.1J to 10 kJ.

13. The method according to any one of claims 1 to 12, wherein the irradiation in step iii) is performed in continuous wave operation with a laser having a power of 1 to 200 watts.

14. Plastic part (a) with at least partial coloration obtainable by the process according to any one of claims 1 to 13.

15. Plastic part (a) according to claim 14, wherein the plastic part (a) is a security document and/or a value document, very particularly preferably an identification document.